1. Field of the Invention
The present invention relates generally to the field of respirator masks.
2. Description of the Background Art
A respirator mask is a device used to deliver a gas or gases to a patient. In its simplest form, the respirator mask includes a face piece, an attaching means, and a gas supply hose. The respirator mask may be used to deliver any variety of gases, including air or oxygen, and a variety of medicines or treatments.
The face piece is fitted over a nose and/or mouth portion of the face of the patient. Preferably, the fit of the face piece against the skin of the patient is substantially airtight and does not allow the supplied gas to escape. A strap or other attaching device holds the face piece against the face of the patient in order to deliver the gas to the patient and also ensures that the face piece forms a seal with the face of the patient.
In a related art respirator mask, the face piece is generally formed of a rigid or semi-rigid shell having a facial seal on the edges thereof. The facial seal contacts the face of the wearer, and is made to be somewhat rigid by having thicker walls in places. Sealing is accomplished in the related art respirator mask by the facial seal in conjunction with a shell contour. The shell contour is generally formed in one or more standard sizes and shapes designed to fit the largest number of wearers.
A drawback is that, except for expensive custom made respirator masks, a related art respirator mask does not conform perfectly to an individual user. The sealing material of the related art respirator mask generally can be compressed only a limited amount, and the related art respirator mask does not adapt well to a face different from the shell contour. Therefore, the related art respirator mask may suffer from a poor gas seal and from pressure points against the face.
Another drawback of the related art is the form of attachment of the mask seal to the mask shell. FIG. 1 shows a related art respirator mask shell and mask seal attachment. The respirator mask of the related art includes a mask shell 3 and a mask seal 1. The mask seal 1 of the related art is generally soft and flexible in order to conform to the face of a wearer and must be capable of being attached to the mask shell 3 so that the respirator mask may be disassembled for cleaning, etc. In FIG. 1 a common related art respirator mask includes an arrowhead-shaped portion 4 on the mask shell 3 that fits into a groove or slot in the mask seal 1. See, e.g., U.S. Pat. No. 5,243,971.
The drawback with this seal attachment arrangement is that the seal is difficult to properly align and attach. The user, especially an elderly person, may not have the manual dexterity needed to align and attach the seal to the mask. In addition, the user may not have enough hand strength to push in and complete a seal that is continuous around a perimeter of the mask. If the alignment is not perfect, the seal may be deformed, affecting both the fit and the airtightness of a seal-mask interface and a seal-face interface.
FIGS. 2A-2B show a second related art respirator mask shell and mask seal attachment. The mask shell 3 includes at least one rigid loop 6 and at least one associated barbed tab 7 that fits underneath the rigid loop 6 and is retained by the rigid loop 6. See, e.g., U.S. Pat. No. 5,724,965.
FIGS. 3A-3B show a third related art respirator mask shell and mask seal attachment. The rigid shell 3 includes apertures 10 and the mask seal 1 includes barbed protrusions 11 that extend through and engage in the apertures 10. See, e.g., U.S. Pat. No. 3,330,273.
There remains a need in the art for an improved respirator mask.
A respirator mask seal and shell are provided according to one embodiment of the invention. The respirator mask seal and shell comprises a mask shell having a face opening, a slot for air passage, and at least one attachment portion spaced around the face opening. The respirator mask seal and shell also comprises a movable interface having a hose connector and a contoured opening adapted to fit against the mask shell. The contoured opening of the movable interface is slidable over the slot and is capable of being positioned on the mask shell over a predetermined range. The respirator mask seal and shell further comprises a mask seal comprising a flexible sidewall having distal and proximal ends and including a rounded outer seal portion located on the distal end of the sidewall, a rounded inner seal portion located between the distal and proximal ends, and a support ring embedded in the sidewall adjacent the proximal end. The inner seal portion is thicker than the outer seal portion and is non-continuous around an inner surface of the mask seal. The support ring includes at least one attachment portion adapted to engage the at least one attachment portion of the mask shell. The proximal end of the mask seal is capable of being removably affixed to the mask shell. The movable interface is capable of being positionally adjusted on the mask shell to suit a wearer. In use, the mask seal is capable of being inwardly deformed by contact with a face region of the user.
A mask seal assembly for a respirator mask is provided according to another embodiment of the invention. The mask seal assembly comprises a mask shell, a mask seal, and a plurality of attachment devices on the mask shell at discrete attachment sites, with the plurality of attachment devices allowing the mask seal to be removably attached to the mask shell.
A seal assembly for a respirator mask is provided according to yet another embodiment of the invention. The seal assembly comprises a mask shell, a support ring, and a mask seal over-molded upon the support ring. The support ring is conformed to assist the mask""seal in retaining a predetermined shape and to facilitate attachment of the mask seal to the mask shell.
A method of creating a seal assembly for a respirator mask is provided according to another embodiment of the invention. The method comprises over-molding an elastomeric mask seal about a support structure to produce a mask seal having an embedded support structure.
A respirator mask is provided according to a further embodiment of the invention. The respirator mask comprises a mask shell having a convex outer surface and a slot therein and a movable interface that movably pivots on the convex outer surface. The movable interface includes a hose connector adapted to receive a gas supply hose and further includes an interior passage that communicates a gas from the hose connector to the slot and to an interior region of the mask shell. The movable interface allows an angular adjustment of the mask shell with respect to a facial plane angle of a user.
The above and other features and advantages of the present invention will be further understood from the following description of the preferred embodiments thereof, taken in conjunction with the accompanying drawings.